Re: [ecasound] lossless conversion broken?

From: Dan Muresan <danmbox@email-addr-hidden>
Date: Sun Oct 31 2010 - 19:46:41 EET

> For low amplitude signals you have quite enough bits in a float, for
> example, for 5 bit amplitude signal you have all the 23 (without sign)
> bits of float mantissa, so no precision loss occurs.

It doesn't appear to be so, for whatever reason. Try this:

# generate sine wave, -40 db, 100 Hz, 1 second
sox -t null /dev/null -b 16 sine.wav synth 1.0 sine 100.0 gain -40

ecaconvert .wav sine.wav
cmp -l sine.wav sine.wav.wav
# or better, lfhex -c sine.wav sine.wav.wav

Why are there bit flips for 0x0003 -> 0x0004 or 0x0000 -> 0x0001? Even
if you go to -60db you will still see these errors.

But to restate my original question -- does ecasound convert to floats
when recording (with no processing), or does it not? I'm not
interested in lossless conversion using ecasound, but I am interestend
in recording.

-- Dan

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Received on Sun Oct 31 20:15:01 2010

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